1. Field of the Invention
The device of this invention resides in the area of locking covers for valve boxes, and more particularly relates to a locking cover including means to assist in jacking the cover out of the valve box to gain access to buried water, gas, petroleum and other process valve operating devices.
2. History of the Prior Art
Locking covers are well known in the prior art as seen in the following U.S. Pat. Nos.:
135,822, 2/18/73, Laforge PA1 969,766, 9/1910, Foley PA1 969,881, 9/1910, Klemm PA1 1,458,391, 6/1923, Burton
The Laforge patent is typical of these locking covers having extended radially-spaced fingers which, upon rotation of a central bolt in one direction, tighten against the sides of the valve box to lock the cover in place and upon rotation in the other direction, move the radially-spaced fingers away from the valve box to release the cover.